Method and apparatus for controlling hill and embankment slides



0. '0. McBEAN. I M E T H O D A N D A P P A R A T U S F 0 R C ONTROLLING HILL AND EMBANKMENT SLIDES.

I APPLICATION men 050.20. ms. 1,323,884. v Patented Dec. 2,1919.

2 SHEETS-SHEET I.

13 I WWII/4; I I

D. D. McBEAN.

METHOD AND APPARATUS FOR CONTROLLING HILL AND EMBANKMEN'T SLIDES.

APPLICATION FILED DEC.20. I915.

Patented Dec. 2, 1919.

2 SHEETS-SHEET 2- marine sre rns rarnnr orrron.

DUNCAN D. MOBEAN, OF NEW YORK, N.

GRAVES, OF CI-I METHOD AN D APPARATUS FOR Specification 0 Application filed December To all whom it may concern:

Be it known that I, DUNCAN D. MoBnAN,

a citizen of the United States, residing at New York, in the borough of Manhattan and State of New York, have invented certain new and useful Improvements in Methods and Apparatus for Controlling Hill and Embankment Slides, of which the following is a specification.

This invention relates to improvements in method and apparatus for controlling hill and embankment slides, and refers more specifically to means for arresting and preventing the encroachment of unstable hills or embankments of earth, rock and the like, upon passageways or other areas menaced by such slides.

It is a matter of common knowledge that canals, railways, roadways and other areas are often menaced by unstable earth or rock adjacent thereto. For illustration, in excavating for a canal or railway it is often necessary to make deep cuts, and very often these cuts extend through valleys or depressions between much higher hills or eleva-. tions. Particularly in the case of canal construction, the water which is admitted to the canalway, after the latter has been excavated, softens the underlying and adjacent strata so that expensive and sometimes disastrous slides occur. The slides which have occurred, and are now occurring, on the Panama Canal are notable examples of the conditions for which my present invention afiords a remedy.

It is the object of the present invention to provide a simple method, and means for carrying the method into effect, for eliminating such hazards from slides.

First describing generally the method of my invention, I first sink one 'or more buttressing structures within, or partly within, the area to be protected from encroachment, 2'. 6., at, or substantially at,the toe of the slide. The buttressing structure or structures are of sufficient dimensions, particularly as to depth, and length in the direction parallel to the advancing movement of the slide, and of such weight that when installed it or they will immovably withstand encroaching movement of the slide both as regards the advancing movement of the slide and as regards any tendency of the slide to underflow and lift up the buttressing structure or Y., ASSIGNOR OF ONE-HALF TO ALBERT H.

roeeo, ILLINOIS.

CONTROLLING HILL AND EMBANKMENT SLIDES.

20, 1915. Serial No. 67,757.

structures. Where the extent of the slide is considerable I prefer, as a matter of economy in cost, to sink a plurality of the buttressing structures extending transversely of the way, 2'. 6., in alinement with the direction of descent of the slide, at spaced apart intervals, and to then sink a retaining struc ture arranged to extend along those ends of the buttresses toward or projecting into the slide; this retaining structure or structures being supported by the ends of the buttressing structures. Of course, if the extent of the slide is small considered in the direction of the length of the way to be protected, the buttressing structure may itself be a sufficient slide retaining structure,'but ordinarily the retaining structure proper will be required, arranged as above described.

Having thus installed the retaining structure or structures, I next proceed to construct the way across the protected area. If a retaining structure has been combined with the buttressing structures the way will,

of course, be constructed in the lee of the retaining structure and above the buttressing structures. In practice, caisson structures will usually be utilized as the buttressing and retaining wall structures, and ordinarily the buttressing caissons will have to be built to extend more or less above the surface level of the way, as, for example, more or less above the bottom level of the canal. Accordingly the construction of the way will involve removing certain portions of the upper parts of the buttressing calssons or structures down to or slightly below the level of the way and thereafter constructing the way proper across or along the Fig. 3 is a transverse vertical sectional view through a bu'ttressing caisson and the adjoining retalning caisson; this view showing the condition after the caissons have been installed but before the canalway'has been constructed, the outline of the latter being indicated in dotted lines.

Fig. i is a plan view showing the manner Fig. 6 is a detail of one of the anti-friction devices between adjoiningv caissons.

Assuming the invention isto be applied to'protect a canalway, and that the slide has :encroached or flowed down upon the way, under ordinary conditions the en-' croaching material will have to come to rest either because of its surface having assumedsits angle of repose or because the most advanced part of the slide has been underflo-wedvby: the weight of the material behind it, and thus'elevated th encroaching parts until the weight of the accumulated upheaved' portions counterbalances the pressure tending to 'advance the slide still farther, so that the Slide as-a whole has come to'rest.

"However, whether the slide has completely come to rest or not, I first erect or place the buttressing caisson orca-issons in position to extend across the canalway, or partly acrossthe canalway, i. 6., in those positions in which they=are to be sunk vertically into place. These buttressing caissons, designated as awhole a in the drawings, may be constructed in any usual or preferred mamier which enables them to be sunk by progressively increasing their weight while excavating beneath them in a working chamber. The caisson construction shown comprises vertical-side walls of sheeting Z) externally smooth, or substantially smooth, and internally reinforced and supported by suitable tilnbering, as for example by the horizontally disposed courses of walling c. The walls are so constructed that they may be increased in height from time to time as theflowering-of the caisson I and the fillingof its interior-with masonry proceeds. Desirably, and as shown, the further reinforcements of 'the'walls are provided by a series of'vertically disposed rods (Z having their lower en'dsattached tothe fioor eof o the caisson and extending upwardly "through the/several "courses of walling, as" shown clearly in Fig." 5. V

5 The floor of the caisson is made amply strong to withstand the full weight offthe ma'sonryewhen the boxpart of the f caisson is -filled with masonry to theniaximum height it/hi ch the caisson is to be built. Moreover, at-he floor is "made airtight, ==or 1 ,seassa the side walls of the caisson are extended downwardly, say-some SlX or seven feet, 2'. 6.,

far enough to enable workmen to work therein. beneath the floor of the caisson, and, as usual, the lower margins of'theseside walls, designated a in the drawings, are made comparatively sharp so as to readily penetrate the eartl. These. sidewalls are also made air-tight, or substantially so. Where the caisson is comparatively. large in area, the working chamber is desirably divided into a plurality transverse partitions f and g,-.these partitions serving to brace the-side :wallsand to support the overlying floor of the caisson,

Suitable shafts are constructed to afford access of the workmen to and from the working chamber, and to enable the air under To form said pneumatic working chamber 7 of compartments by pressure to be introduced-and the excavated material to be removed. In the buttressing caisson now being described,-a plurality of these shafts h are provided, spacedat intervals apart throughout the length of the ca1sson.

Each caisson is provided with a suitable air-lock i of any usual or preferred construction and serving the usual functions. As-wi-ll be well understood by those skilled in the art and familiar with caisson'practice, masonry or filled in to the caisson box so as to progressively increase the weight of the. caisson structure is a whole as the excavation underneath -"it proceeds; the caisson being thus gradually forced downwardlyas fast as the excavation proceeds, and the added weight in the caisson serving to overcome thein creasing frictional resistance on the sides-of the caisson. I prefer to 'use'concret-e' 70' for filling in the caisson; progressively around the shafts, inasmuchas this material can be put in in semi-liquid orplastic stateandsis comparatively'heavy. However, the caisson structure will ordinarily have to be' "built and carried up toaheight above 'thebottom level of the canalway or roadway-Pin order that *it shallhave sufiicient "weight to overcome the resistance to .its descent. Accordingly and as a'm'att'erofeconomy-ofconstructi'on, I prefer to'fill inthatpartdf the caissonwhich will be above thebottom'level of the 'canalway or roadway in the :final'pd sition of the" caisson, with: weighting material which may be readily removed. "Prefer-o ablyI employ broken stone-or broken-1Com crete j,-which maybe either piled.in"heterogeneously or'may be laid in courses so as to form true masonry construction. Concrete might,:however,. be deposited throughout the fullfdepth of the caisson box, and thosep ortions' thereof which @XFfifidd" @bQVt t other heavy material is sired final level of the way be blasted out or otherwise removed.

.Having constructed and sunk in place the buttressing caisson, or a series of buttressing caissons, spaced apart at suitable intervals, I next proceed to place the retaining caissons, designated in the drawings as a whole Z, in such position that they extend along the ends of the buttressing caissons and between the latter and the slide. That is to say, the retaining caissons are sunk adjacent to the ends of the buttressing caissons so as to overlap and be supported by the ends of the latter and so as to form in effect retaining walls. which receive the direct lateral thrust of the slide. The retaining caissons Z are preferably constructed substantially like the described caissons (1, except that they will ordinarily be carried up somewhat higher than the buttressing caissons, preferably at least as high as the depth of the canal, and

they may be filled in with solid concrete to their full height. Parts of the retaining caissons corresponding to those of the buttressing caissons are correspondingly lettered.

Inasmuch as the retaining caissons may be forced into bearing withthe buttressing caissons while the former are being sunk, I prefer to provide anti-friction devices between the adjoining parts of the caissons. These anti-friction devices may be rollers, as indicated at m, orsome simpler device, for lessening the friction, as for example steel plates.

It will, of course, be understood that inasmuch as the buttressing and retaining caissons are sunk independently of each other, it by no means follows that they must both be sunk to the same depth. The end of the buttressing caisson should afford such extent of bearing and support for the side of the retaining caisson that there will be no tendency of the latter to tilt over under the weight of the slide. The length, depth and weight of the buttressing caisson should be such as to make of it an immovable, or substantially immovable, buttress, and this stability will be enhanced, of course, when the retaining caisson is installed. Itv will be obvious that the length and depth, and therefore the weight, of the buttressing caissons will be such as to suit the conditions of the particular problem in hand. If the sub-strata are soft and yielding to a depth below that reached by the bottom of the buttressing caisson, the latter will be sunk deep enough so that the superposed load of masonry renders it secure against the underflowing lifting tendency of the slide. On the other hand, if solid foundation be reached, the caisson need only be sunk far enough into such foundation to anchor it firmly against lateral movement. There will hereinbefore the proposed passageway;

structures as in such case be no substantial tendency of the slide to lift the caisson, and the latter need-therefore only extend down to the firm stratum. In case the canal or other way be formed between two slides, both of which must be guarded against, it is of course obvious that retaining caissons will be sunk at both ends of the buttressing caissons, and in that case the combined caisson structure, 2'. 6., the retaining caissons at each side and the buttressing caisson between, will form in effect arches between the two slides.

The construction of the canal, roadway or other surface above the buttressing caissons, after the structure as a whole has been placed, requires no special description. It will be observed that the length of the transversely disposed buttressing caissons is a little greater than the bottom width of the canal, so that the end walls of these buttressing caissons may be left intact when the canalway is built. After the retaining caissons have been placed it will ordinarily be desirable to cover them with earth extending from the canal side of the caisson upwardly and backwardly at .a safe angle of repose. By thus covering them any tendency to tilt over toward the canal will be minimized.

It will be obvious that the details of con struction and arrangement may be considerably varied without departing from the invention, and the appended claims are to-be construed as broadly as is' commensurate with their terms and the state of the art.

I claim as my invention:

1. The method of making and protecting a passageway through a section of land that is liable to produce slides, progressively sinking a plurality of buttressing caisson structures in such a manner that they will lie in spaced apart relationship and individually extend entirely across of sinking one or more retaining caissons parallel with the sides of said passageway and so positioned as to lie between the slide developing earth and the ends of the buttressing caisson structure and project above the height of the latter; and finally of grading down the upper portion of the buttressing caisson far as the lower level of the said passageway.

2. The method of protecting a passageway menaced by a slide, which consists in sinking an abutment caisson to extend beneath and transversely of said passageway, and then sinking a retaining structure to extend along the way, between the encroaching part of the slide and said abutment caissons and supported by the latter.

3. The method of protecting a passageway menaced by a slide, which consists in sinking an abutment caisson to extend beneath and transversely of said passageway,

which consists of 'andinstalling a retaining structure to exend. lon the W y, tw e the enc o c ing part of the slide and said abutment caisson and supported by the,latter.

4. The method of protectingv apassageway. menaced by an earth slide, which ,con-

sists in sinking, inspacedapart relation, a

plurality of buttressing caissons, arranged to underlie and extend, transversely of,sa1d

'way, weighting said caissons so that they will immovably withstand lifting under the underflowing action of the slide, and installing a retaining structure-alongside of said way, between the encroaching' ,part of the slide and the ends of the abutmentcaissons and supported by the latter. I

5. The method of; protecting a passageway menaced by an earth slide, which consists in sinking, in spaced apart re1ation, a plurality of buttressing .CZHSSODS, arranged to underlie, and eXtend transversely of, said I way, weighting saidcaissons so that they will immovably withstand lifting under the underflowing action of the slide, and sinking .a retaining caisson or caissons along-j of the slide and saidrabutment caisson or caissons and finally removing .the upper portions of the buttressing caissons down to the level of the bottom. of the proposed way and constructing the latter above saidbuttressin-g caissons. t

7. In-a slide retaining, construction, the combination of a caisson embedded in front of. and-obstructing the slide, andv a buttress- .ing caisson, extending laterally from the obs nu t ne Q si Qauit b em ed l ea weighted with a'heavy filler and ib u'tte'd Iagainst :theside .wall of the obstructing caisson-to hold the. latter againstlateraldisplacement duelto thepressure of the slide.

8. In a slide retaining construction, the

combination. of ,a plurality ofcaissons embedded end to end along the frontof and obstructing the slide, and. a plurality of b uttressing caissons spacedapart and, extend laterally from the obstructingcaissons, said buttressing caissons being su tably embeddedand weighted with 'a heavy filler andbutted against the side .walls of the obstructing caissons to. hold the .latter against lateral displacement due to the pressure of the slide. i

.9. .The method of protecting a proposed passageway from the encroachment of em-.

bankment slideswhichconsists in building one-or' more buttressingstructures at right anglesv to the proposedpassageway, said structures being of greater .width than said proposed passageway and terminating at the upper level. thereof, and in removing the upper portions of the structure and in constructing the passageway in the opening produced by such removal.

I .10. The method ofprotecting a proposed roadway from embankment slides vWhich consists in building and sinking a plurality of spaced apart, parallel buttressing structures greater in ,width than the proposed roadwayand at right angles thereto,,'.said structures to be sunkfltosu'ch depth that the upper portions thereof are at alevel with the top of the proposed roadway; in removing the upper portions'of said structures to.

a depth andlwidth of the proposed roadway; and. in finally building the roadway inthe channel so produced.

' DUNCAN D. MoBEAN Witnesses: 7

H. 0. Toxistmr, 

